Armin Haag

Das verhalten von tetraorganozinn-verbindungen gegenüber flüssigem schwefeldioxid

Abstract In contrast to (n-C4H9)4Sn and (C6H5)4Sn, (CH3)4Sn and (C2H5)4Sn absorb one mole of SO2 at −20° to yield the corresponding penta-coordinate, colourless, stable trialkyltin alkanesulfinates, R3SnO2SR (R = CH3, C2H5). While (CH3)4Sn at 60° reacts with liquid SO2 to give in high yields bis(trimethyltin) sulfate, [(CH3)3Sn]2SO4, a mixture of hexa-coordinate diethyltin bis(ethanesulfinate) and bis(triethyltin) sulfate was obtained from (C2H5)4Sn and SO2. On the basis of infrared, Raman, 1H NMR, Mossbauer, and mass spectroscopic investigations, all the compounds described here are double O-sulfinato and sulfato complexes respectively.

Die komplexchemie polyfunktioneller liganden : XXVIII. Über die selektive spaltung von arsenphenyl-bindungen mit jodwasserstoff in nichtwässrigen systemen☆

Abstract The phenylalkyl arsines (CH 3 ) 2 AsC 6 H 5 , CH 3 As(C 6 H 5 ) 2 , C 2 H 5 As(C 6 H 5 ) 2 , (CH 2 ) n [As(C 6 H 5 ) 2 ] 2 ( n = 1, 2), and C[CH 2 As(C 6 H 5 ) 2 ] 4 react with liquid or gaseous HI in nonaqueous solvents by selective cleavage of the arsenicphenyl bonds yielding (CH 3 ) 2 AsI, CH 3 AsI 2 , C 2 H 5 AsI 2 , (CH 2 ) n (AsI 2 ) 2 and C(CH 2 AsI 2 ) 4 . The latter forms the tetradentate ligand C[CH 2 As(CH 3 ) 2 ] 4 with CH 3 MgI. The electron impact mass spectra of these compounds show clear fragmentation patterns resulting mainly from the formation of fragments with AsAs bonds or (As) n clusters ( n = 3, 4). From CH 3 AsI 2 and C 2 H 5 AsI 2 the iodine-free cycloarsines (AsCH 3 ) 3 , (AsC 2 H 5 ) 3 , (AsC 2 H 5 ) 4 , As 3 (C 2 H 5 ) 2 CH 3 and As 4 (C 2 H 5 ) 3 CH 3 are formed by thermal secondary reactions in the high temperature inlet systems of the mass spectrometer. The fragmentations of the cycloarsines and the other compounds are discussed. The infrared spectral absorptions of all the alkyl iodoarsines can be completely assigned in the range of 4000 – 250 cm −1 . The IR data of C 2 H 5 AsI 2 indicate the existence of trans and gauche rotational isomers.

Über ψ-tetra-, penta- und hexakoordinierte sulfinatokomplexe des zinns

Abstract Colourless, stable, polymeric, ψ-tetrahedrally coordinated O -sulfinates of divalent tin, Sn(O 2 SR) 2 , were obtained by reaction of SNCl 2 ·2 H 2 O with sodium organosulfinates, NaO 2 SR (R = p -CH 3 C 6 H 4 , C 6 H 5 ), in ethanol. Colourless penta- and hexa-coordinated double O -sulfinato complexes of the type (C 6 H 5 ) 3 SnO 2 SR, (C 6 H 5 ) 2 Sn(O 2 SR) 2 and (CH 3 ) 2 Sn(O 2 SR) 2 were formed respectively by reaction of triphenyltin chloride and diphenyl- and dimethyltin dichloride with sodium organosulfinates, NaO 2 SR (R = p -CH 3 C 6 H 4 , C 6 H 5 , CH 3 ), in THF. The structural investigations were performed with the aid of infrared, Raman, Mossbauer, and mass spectroscopy.

Two proanthocyanidins from the bark of Dalbergia monet̊ari

Abstract In a chemical investigation of the bark of Dalbergia monetaria the two new proanthoeyanidins (2 R ,3 R ,4 R )-3,3′,4′,7-tetrahydroxyflavan-(4β→8)-epicatechin and (2 R ,3 R ,4 R )-3,4′,7-trihydroxyflavan-(4β→8)-epica-techin were isolated.